* WHAT...Very cold wind chills as low 25 to 40 below zero expected. * WHERE...Lower Kuskokwim Valley from Kalskag to Stoney. * WHEN...From 6 PM this evening to 6 PM AKST Monday. * IMPACTS...The dangerously cold wind chills as low as 40 below zero could cause frostbite on exposed skin in as little as 10 minutes. Frostbite and hypothermia are likely if exposed to these temperatures. * ADDITIONAL DETAILS...An Arctic airmass continues to settle in over the area. This bout of cold weather will be prolonged over the next few days and into next week. The coldest wind chills will occur during the overnight and early mornings.